PSIG wrote: ↑Wed May 31, 2023 6:06 pm
@JHolland - I have seen variable input/output delays, but consistent with little jitter or scatter in most setups with little variation moving from cylinder-to-cylinder with a timing light, on ones I've checked. Timing table compensation is simple for this overall effect, as it is relative.
But are you saying C-to-C variation or per-cylinder scatter is a normal or expected effect you have seen?
Should I see this variation on the crank angle with a timing light every 720°/n-cylinders apart (as one example test)?
I agree a v2 code base using 'conventional' interrupt should be investigated as a useful improvement from a variety of perspectives. Unless of-course someone's other code, patent, or other block is preventing that, or otherwise forcing scheduling.
I have seen jitter out to around 100us, a heat map shows a curve that I would guess would be roughly similar to an exponential decay with the majority of events within something like 20us and a few outliers at 100us. You won't see it with a timing light because you won't have the persistence.
The blocker for a new code base is that someone would need to take the time to design a new board with the cam, crank, ignition and injection I/O connected to the IC and OC pins, I have been working on one for my own use but it isn't going to be a universal board.